Elevator and door and loading mechanisms therefor

ABSTRACT

A dumbwaiter-type elevator capable of being employed in an elevator shaft having hatchways disposed at peripherally spaced locations therearound. To accommodate the peripherally spaced hatchways the elevator car is provided with a rotatable loadsupporting carriage and self-contained driving and indexing mechanisms for the carriage. The carriage is provided with selectively extensible and retractable load-transferring mechanism to accommodate the smooth transition of a load between the hatchways and the car and maintain the load in a level condition while in the car. The car also carries powered closure members which are movable between open and closed conditions relative to the load-supporting carriage. The hatchways are provided with doors and a selectively operable mechanism is provided to move the doors between open and closed conditions responsive to corresponding movement of the closure members. A common hydraulic power circuit carried by the car powers all mechanisms supported on the car and, through the operation of the closure member, also powers the hatchway doors.

United States Patent Harold Marven Peterson San Francisco;

' Scott F. Andersen, Fairfax, both or Calif. [21] Appl. No. 884,652

[22] Filed Dec. 12, 1969 [45] Patented Dec. 28, 1971 [73] Assignee San Francisco Elevator Company, Inc.

San Francisco, Calif.

[72] Inventors [54] ELEVATOR AND DOOR AND LOADING Primary Examiner-Gerald M. Forlenza Assistant Examiner-Lawrence J. Oresky Attorney-Naylor & Neal ABSTRACT: A dumbwaiter-type elevator capable of being employed in an elevator shaft having hatchways disposed at peripherally spaced locations therearound. To accommodate the peripherally spaced hatchways the elevator car is provided with a rotatable load-supporting carriage and self-contained driving and indexing mechanisms for the carriage. The carriage is provided with selectively extensible and retractable load-transferring mechanism to accommodate the smooth transition of a load between the hatchways and the car and maintain the load in a level condition while in the car. The car also carries powered closure members which are movable between open and closed conditions relative to the load-supporting carriage. The hatchways are provided with doors and a selectively operable mechanism is provided to move the doors between open and closed conditions responsive to corresponding movement of the closure members. A common hydraulic power circuit carried by the car powers all mechanisms supported on the car and, through the operation of the closure member, also powers the hatchway doors.

PATENTEunzceelsn 315303 1 9 sum 2 or a INVENTORS PAIENTEU nines lsn SHEET 3 UF 8 IN VENTORS HAROLD MAKVEN PETERSON H I SCOTT FKfDER/CK ANDEKSEN BY s q k ATTOKNEV5 PATENTED 0522s an SHEET 8 OF 8 INVENTORS HAKULD MflKVfA/ Ff/YAWN EMU FKEDfK/CK ANDEKSEN QNN\ QQNV $3 @NN mfi Qm- 3 -P- MIHH $N 3 w 3 3 3 v f Mg 1 3 -l\ I.JB..I.. W g s F.| ,/I|/\ ELEVATOR AND DOOR AND LOADING MECHANISMS THEREFOR BACKGROUND OF THE INVENTION The present invention relates to the art of elevators and, more particularly, to robot operated dumbwaiter-type elevators.

In the prior art, robot-operated dumbwaiters are known. U.S. Pat. No. 3,260,330 suggests an automatic door system for dumbwaiters. U.S. Pats. Nos. 3,37,789 and 3,337,070 suggest power-operated loading and unloading mechanisms designed for use in dumbwaiters.

The art of dumbwaiters dates back to at least the time when Thomas Jefferson installed his dumbwaiter at Monticello. The aforenoted patents are merely cited as being representative of the art to which the present invention relates. As compared to these patents, the present invention is considered an improvement in that it provides greatly simplified loading and unloading mechanisms and a simplified door-operating mechanism. The loading and unloading mechanism employs an extensible transfer device capable of being powered by a single hydraulic cylinder, as contrasted to the involved rotary drive train arrangements customary in the art. The door-operating mechanism also is capable of being powered by a single hydraulic cylinder and is adapted to simultaneously operate both a car carried closure member and a hatchway door. The employment of simple hydraulic actuators enables the mechanisms of the present invention and the hydraulic power source therefor to be carried by the elevator car.

In addition to providing the aforenoted simplified loadtransferring and door-operating mechanisms, the dumbwaiter of the present invention also has the advantage that it is capable of servicing a plurality of hatchway doors disposed at peripherally spaced locations around an elevator shaft. This is accomplished through the employment of a carriage suspended within the elevator car for rotation relative thereto about an axis extending generally centrally and longitudinally of the shaft. The carriage is selectively rotated through means of an hydraulic actuator and, similarly to the aforedescribed hydraulic actuators, may be supplied with fluid power from a common hydraulic source carried by the car. Alignment, indexing and leveling mechanisms are incorporated into the carriage to function in response to the operation of the loadtransferring mechanism.

SUMMARY OF THE INVENTION The invention is made up of the mechanisms briefly described in the foregoing discussion and may be said to reside in these individual mechanisms and their combination. The basic elements of the combination comprise an elevator shaft having hatchways at peripherally spaced locations therearound and an elevator car movable within the shaft. The car is provided with selectively operable closure members disposed therearound so as to be in opposition, respectively, to the peripherally spaced hatchways of the shaft. A carriage is supported on the car for rotation relative thereto about an axis disposed generally centrally of the shaft and extending longitudinally thereof. The carriage is provided with a load supporting surface and carries a transfer mechanism for selective extension and retraction to facilitate the transfer of loads to and from the load-supporting surface and a hatchway aligned therewith. In this basic combination, a first operating mechanism is provided to selectively operate the respective closure members, a second operating mechanism is provided to selectively rotate the carriage, and a third operating mechanism is provided to selectively effect the extension and retraction of the transfer mechanism.

Additional facets of the invention and its detailed structured and operation will become more apparent when viewed in light of the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view, with parts thereof broken away for the sake of simplicity, illustrating the elevator car, the rotatably supported carriage mounted thereon, and one of the closure members carried by the car.

FIG. 2 is a cross-sectional plan view taken through the elevator car and shaft on a plane disposed slightly below the upper bearing support for the rotatably mounted carriage.

FIGS. 3 and 4 are cross-sectional views taken on the planes designated by lines 3-3 and 44, respectively, of FIG. 2.

FIG. 5 is a plan view of the transfer mechanism carried by the rotatably mounted carriage, with the parts to either side of the mechanism broken away for the sake of simplicity.

FIGS. 6, 7 and 8 are cross-sectional views taken, respectively, on the planes designated by lines 6-6, 7-7, and 88 of FIG. 5.

FIG. 9 is an elevational sectional view illustrating one of the closure members carried by the car and the hatchway door cooperating therewith.

FIG. 10 is a cross-sectional plan view illustrating one of the closure members carried by the car and the hatchway door cooperating therewith with parts thereof broken away for the sake of illustration.

FIG. 11 is a cross-sectional view taken on the plane designated by line 1 l--l1 of FIG. 9.

FIG. 12 is a perspective view illustrating in broken-away section one of the mutually engageable pin and receptacle combinations, together with the cam actuator therefor, employed to impart movement of the car carried closure members to the hatchway doors.

FIG. 13 is a front view of one of the receptacles of the combination illustrated in FIG. 12, with phantom lines illustrating alternative positions which may be assumed by the pin cooperating therewith.

FIG. 14 is a schematic view illustrating the hydraulic circuit employed to power the various mechanisms carried by the elevator car.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Car Superstructure Referring now to FIG. 1, the car is designated therein in its entirety by the numeral I0 and is shown as having a superstructure comprised of comer members I2, I4, 16, and 18 interconnected by crossmembers 20, 22, 24, and 26. In addition to the latter crossmembers, the superstructure is also provided with corresponding crossmembers running at generally right angles to these crossmembers, as designated by the numerals 28 and 30, respectively, in FIG. 2. The crossmembers 20 and 22 have bearing support members 32 fixedly secured therebetween and the crossmembers 24 and 26 have bearing support members 34 fixedly secured therebetween.

The basic superstructure also comprises additional crossmembers 36, 38, and 40 disposed to the exterior of the corner members on three sides of the car (see FIG. 2) to support part of the carriage-indexing means, as will be developed in detail subsequently. Only three such members are provided because the carriage of the illustrated car only indexes in three positions, to align with the sides of the elevator shaft designated in FIG. 2 by the numerals 42, 44 and 46, respectively. The fourth side of the shaft is identified by the numeral 48 and the shaft is designated in its entirety by the numeral 50. From FIG. 2 it can be seen that the side 48 has angle-shaped support rails 52 fixedly mounted thereon and that gliders 54 mounted on the ends of the crossmembers 20, 22, 24, and 26 (only gliders on the members 24 and 26 appear in FIG. 2) support the superstructure in slidable engagement with the rails. In operation, the rails 52 and gliders 54 function to guide the car within the shaft from one level to another. While not illustrated, it should be understood that a plurality of levels would typically be provided and that conventional structure would be employed to selectively move the car within the shaft from one level to another.

The basic superstructure of the car is completed by closure member supporting frameworks supported on the sides thereof facing the sides 42, 44, and 46, respectively, of the elevator shaft. These frameworks correspond identically in construction and, accordingly, only one will be described in detail and like numerals will be employed to designate corresponding elements of each of the frameworks. Referring now to FIG. 1, the single framework illustrated therein is designated in its entirety by the numeral 56. The primary elements of the framework comprise opposed channel members 58 and 60 mounted on the ends of the crossmembers extending to the side of the superstructure supporting the framework. In FIG. 1, only the ends of three of these crossmembers are illustrated. The lower crossmember is the same as that previously identified with respect to FIG. 2 by the numeral 30. The upper crossmembers are identified by the numerals 62 and 64 and, although not illustrated, it it should be understood that these would extend entirely across the superstructure similarly to the crossmembers 28 and 30. The lower ends of the channel members 58 and 60 are provided with inwardly angled extensions 66 and 68 and a channelshaped support member 70 is fixed therebetween. The basic framework is completed by a vertically extending T-shaped track 72 fixed to and extending between the support member 70 and the crossmember of the superstructure thereabove (24 as viewed in FIG. I) and a pair of vertically extending cam plates 74 fixed to and extending between the support member 70 and the crossmember thereabove to either side of the track. The cam plates are straight over the length extending between the support member 70 and the crossmember thereabove and provided with inwardly bent distal portions, designated 76, at their upper ends.

CAR CLOSURE MEMBERS AND HATCI-IWAY DOORS Each of the frameworks 56 supports a closure member and operating mechanism therefor. Since these members and the mechanisms correspond to one one another, only one will be described in detail and like reference numerals will be used to designate corresponding elements of the respective members and mechanisms. The closure members and mechanisms may best be seen from the illustrations of FIG. 1 and FIGS. 9 to 13.

Referring now to FIG. I, there it can be seen that the closure member, designated 78, is slidably received between the channel members 58 and 60. In the condition illustrated, the member is in a lowered open condition relative to the car. It is slidably received between the channel members 58 and 60 for movement between this condition and an elevated closure condition (see FIG. 9). The operating mechanism for the closure member is mounted on a pair of bracket members 80 fixed to and extending laterally from the underside of the support member 70. The mechanism, designated in its entirety by the numeral 82, comprises as its basic element a double acting hydraulic cylinder 84 having the piston rod thereof, designated 86, extending from its upper end. Conventional fluid pressure connections 88 and 90 are provided at either end of the cylinder. The cylinder is adjustably mounted on the bracket members 80 through means of threaded tie rods 92 extending between end plates 94 and 96 mounted at either end of the cylinder. The ends of the tie rods are fixedly secured to the respective end plates and adjustment nuts 98 (see FIG. 9) received on the tie rods to either side of the bracket members 80 provide for the adjustable securing of the tie rods to the members.

Referring now to FIG. 9, there it can be seen that the upper end of the piston rod 86 is secured to a bracket 98 which, in turn, is fixed to a follower H slidably received on the track 72 for up and down movement responsive, respectively, to extension and retraction of the piston rod. The follower comprises, as can be seen from FIGS. 9, l0 and 11; a pair of opposed sideplates 102; upper and lower glides m4 and 106 secured between the sideplates in slidable engagement with track 72; a pair of upright angle members I06 fixed to the sideplates in opposed spaced relationship; and, upper and lower belt-guiding rollers 108 and 110, respectively, rotatably mounted between the angle members 106 in spaced parallel relationship on bolts 112 fixed between the angle members. The rollers I08 and have a closed loop belt 114 trained therearound for rolling engagement therewith. The inner reach of the belt Hi4, designated I16, is fixedly secured to the track 72 by a bracket 118, The outer reach of the belt, designated 120, is fixed to the closure member 78 by a bolt E22.

The bracket I18 provides for both fixing of the belt to the track 72 and fabrication of the closed loop of the belt from a length of straight belting material. The bracket comprises, as can best be seen from FIGS. 9 and 11, a pair of clamping members 124 having clamping surfaces disposed in opposed facing relationship in engagement with the free ends of the length of belting making up the belt 1-14. Bolts 126 extend between the clamping members to secure the clamping surfaces of the member in secure engagement with the free end of the belt. The ends of the clamping members opposite the clamping surfaces thereof are bifurcated and bolted to the distal leg of the T-shaped track 72.

Through the aforedescribed arrangement of the hydraulic cylinder 84 and belt 114, movement of the piston rod 86 by an increment of one functions to move the closure member 78 by an increment of two. This multiplying effect results because the piston rod, together with the carriage 100, functions to move the entire belt as a unit by an increment corresponding to the increment of movement of the rod while, at the same time, the outer reach of the belt functions to move the bolt 122 relative to the carriage 100 by a corresponding increment.

The hatches of the elevator shaft 50 correspond identically in construction and are each identified by the numeral 128. Each hatchway is provided with a slidable biparting door of relatively conventional construction normally counterbalanced to a closed condition. The lower panels, designated 130, of the respective biparting doors are mounted in the elevator shaft for movement in paths parallel to the paths of the respective closure members 78. The slidable mounting is provided by channel members 132 disposed to either side of each of the hatchways, between which members the panels are received. While not illustrated, it should be understood that the upper panels of the biparting doors would be mounted similarly to the lower panels and that conventional tying structure would function to couple the operation of the upper and lower panels of each door so that they would simultaneously open and close.

Each of the closure members 78 carries a pair of slidably mounted actuating pins 134 disposed, respectively, in alignment with the cam plates 74 of the framework supporting the closure member. These pins are spring biased to a normally retracted condition, as illustrated in FIG. 9, by compression coil springs 136 received therearound and provided with bearing heads or followers" 138 slidably engageable with the cam plates 7d. Through the aforedescribed interrelationship, movement of a closure member 78 to the closed condition, as illustrated in FIG. 9, functions to retract the pins 134 associated therewith and movement of a closure member out of this condition towards the open condition functions to extend the pins associated therewith. The length of travel of a closure member required to effect extension and retraction of apin associated therewith is determined by the distal portion 76 of the cam plate 74 associated with the pin. This can be ap, preciated from FIG. 9 wherein the pin 134 is shown retracted in a position at the far end of the distal portion 76 and extended (see the phantom line representation) in a position supported on a straight length of the track 72.

The lower door panel 130 of each hatchway door has mounted thereon a pair of pin receiving receptacles 140 disposed, respectively, for alignment with the pins 134 of the closure member disposed for aligned opposition with the door. This condition of aligned opposition may be seen from FIG. 9 and occurs when the car is in alignment with a hatchway. In this condition, lowering of the closure member 78 functions to extend the pins 134 carried thereby into engagement with the receptacles M0 and, as a result, movement of the closure member functions to impart corresponding movement to the lower panel of the hatchway door. The interrelationship of a pin and a receptacle cooperating therewith may best be seen from FIG. I2 wherein the pin 134 is shown in the condition which it assumes shortly after traveling from the distal portion 76 of the cam plate 74 to the flat portion thereof. During this movement, the pin is first extended into the enlarged upper portion of the receptacle 140 and then forced into gripping engagement with the lower bifurcated portion of the receptacle. In the latter condition, the pin functions to impart movement from the closure member 78 to the lower hatchway door panel 130.

FIG. 13 illustrates the detailed construction of one of the receptacles 140. There it can be seen that the receptacle is formed as an integral member having an enlarged upper portion 142 an elongated bifurcated lower portion 144 and a short upper bifurcated portion 146. In the preferred embodiment, the receptacle is formed of a tough resilient plastic material, such as the material LEXAN manufactured by the General Electric Company. In operation, the pin initially enters the enlarged upper portion 142 and is forced into gripping engagement with the lower bifurcated portion 14 4 upon movement of the closure member towards the open condition. Normally, the pin is retained in gripped engagement with the lower portion during movement of the closure member both to and from the closed condition. Upon reaching the closed condition, the pin is again forced into the enlarged upper portion 142, from whence it retracts under the influence of the spring 136. In the event that the door panel of the hatchway door encounters excessive resistance during its movement by the pin 134, the pin may slide out of the lower bifurcated portion in either direction, depending upon the direction of movement of the closure member 78. The degree of excessive resistance required to thus release the pin is dependent upon the degree of frictional engagement between the bifurcated lower portion 144 and the pin.

During normal operation, the closure members 78 are all in a closed condition during traversal of the elevator car from one level to another. Thus, during movement of the car from one level to another, the pins 134 are normally maintained in a retraced condition and do not act upon the hatchway doors. Should a pin for some reason be extended (e.g., by inadvertent positioning of the closure member associated therewith in an open condition) during traversal of the car from one level to another the bifurcated ends 144 and 146 permit the pin to pass therethrough without damage to the receptacles 140 and the associated hatchway doors. It is noted that the bifurcated end 146 normally resists movement of the pin therethrough, but that in the event of excessive force, it resiliently deflects to permit passage of the pin without damage.

ROTATABLE CARRIAGE Referring now to FIG. 1, the rotatable carriage is designated therein in its entirety by the numeral 148. It comprises, as its basic elements, a rectangular framework 150 comprised of top and bottom members 152 and 154, respectively, rigidly interconnected by side members 156. The framework 150 is mounted for rotation about an axis, designated 15%, extending longitudinally through and centrally of the car and the elevator shaft. This mounting is provided by an upper bearing assembly 160 interposed between the bearing support members 32 and the top member 152 and a lower bearing assembly 162 interposed between the bearing support members 34 and the bottom member 154. As can be seen from FIG. 3, the upper bearing assembly 160 comprises a plate 164 fixed to the bearing support members 32 and the bearing stud depending downwardly from the plate into engagement with the top member 152. The lower bearing assembly comprises a plate I65 fixed to the bearing support members 34 and a bearing member I66 joumaled relative to the plate and fixed to the bottom member 154.

The carriage Md is selectively rotated about the axis 158 into alignment with the respective hatchways through means of an hydraulic motor I68 mounted on the bearing support members 34 in driving engagement with the bearing member 166. Indexing means, as will be described in detail in the subsequent discussion, function to lock the carriage in alignment with a particular hatchway during loading and unloading operations.

LOAD SUPPORTING TABLE The carriage M8 supports a load-supporting table, designated in its entirety by the numeral 170, for rocking movement about a generally horizontal axis. The basic structure of the table is made up of a framework comprising: a pair of longitudinally extending side members, each of which is defined by a plate 174, angle 176, and channel 178 fixedly interconnected with one another (see FIG. 4); a pair of longitudinally extending intermediate members 180 of channelshaped cross section; side member hanger brackets 182 fixed to and depending downwardly from the opposite ends of each of the side members 172; crossmembers 184 fixed to and extending between the transversely aligned hanger brackets on the respective side members; intermediate member support brackets 186 fixed to and extending upwardly from the crossmembers 184 into fixed supporting engagement with the opposite ends of each of the intermediate members 180; and, fastening brackets 188 fixed to and extending inwardly and rearwardly from each of the intermediate member support brackets 186. The table is supported for rocking movement relative to the carriage 148 by a pair of transversely aligned bearing assemblies 190 mounted between the side members T56 of the carriage framework and the side members 172 of the table framework. These assemblies may take any suitable form and are shown as comprising base elements 192 fixed to the side members 156 and journal members 194 fixed to the side members 172 and joumaled within the base members for rotation relative thereto.

The basic structure of the load supporting table is completed by a plurality of rollers 196 rotatably mounted between each side member 172 and the intermediate member 180 opposed thereto. These rollers, as will become more apparent from the subsequent discussion, function to support a load carried by the elevator for ready shifting to and from the loaded condition.

TRANSFER MECHANISM The basic element of the transfer mechanism comprises a subcarriage, designated in its entirety by the numeral 198, slidably received between and supported on the intermediate members 180. The primary element of the subcarriage is made of a framework comprising: a pair of longitudinally extending side members 200 of double-angled cross-sectional configuration (see FIG. 4); a pair of longitudinally extending intermediate members 202 of box-shaped cross section fixed, respectively, to the side members 200; and, a center member 204 fixed between the intermediate members 202. The side members each have a pair of longitudinally spaced channelshaped brackets 206 extending laterally therefrom in encompassing relationship to the lower flange of the intermediate member 180 in opposition thereto. These brackets, in turn, carry low friction gliders 208 which slidably engage the flanges and, thus, function to guide the subcarriage for slidable movement along the intermediate members 180.

The center member 204 carries an upwardly disposed roller 210 and a pair of transversely aligned downwardly disposed rollers 212. The roller 210 functions, as can be seen from the phantom line extended illustration thereof in FIG. 3, to lend support to the leading end of a cart upon its transition from a hatchway into the elevator car. The rollers 212, as will be described in detail in the subsequent discussion, function to maintain the subcarriage 198, and thus the load-supporting table 170, in a level condition when the transfer mechanism is retracted.

The subcarriage 198 is selectively extended and retracted relative to the table 170 through the operation of a double acting hydraulic cylinder 214 having its rearward end fixed to a plate 216 mounted on the rearward crossmember I184 and its piston rod 218 secured to the center member 204. Through this mounting arrangement, extension and retraction of the piston rod functions, respectively, to extend and retract the subcarriage 198 relative to the table 170.

The subcarriage. 198 also carries belt-guiding rollers 22!) rotatably mounted on the side members me. One pair of such rollers is mounted on each of the side members to provide for the support of a closed loop belt 222 thereon. As mounted on the rollers, the belts are disposed so that the upper and lower reaches thereof, designated 224 and 226, respectively, extend parallel to the path of the carriage. A point on the lower reach of each belt is fixedly secured to the fastening bracket 188 disposed therebeneath by a bolt 228 (see FIG. 4). The upper reaches of the belts are secured to and carry a load transferring head 230 disposed thereabove. The head, in turn, carries a pair of electromagnets 232.

Through the foregoing arrangement of the subcarriage 198, cylinder 214, and belts 222, the motion imparted to the loadtransferring head 230 is multiplied by a factor of two as compared to the movement of the piston rod 218. The explanation of this multiplying effect is identical to that found in the foregoing discussion of the operating mechanism for the car closure member.

The operation of the transfer mechanism in the loading or unloading of the elevator can best be seen from FIG. 3. In this figure, the elevator car is shown aligned with a hatchway to the left of the car having a load-carrying cart 234 (as shown in phantom line representation) supported thereon. This cart is of relatively conventional construction in that it comprises a load-carrying body 236 supported on castorlike wheels 238. It is especially designed, however, for employment with the elevator of the present invention in that it is provided with a pickup plate 240 fabricated of a ferrous material and runners 242 disposed for rolling engagement with the rollers 196 of the car and similar rollers 244 mounted in the sill of the hatchway upon movement of the cart to and from the elevator car. The disposition of the runners 242 relative to the wheels 238 and the rollers 196 and 244 is such that engagement of the runners with the rollers functions to lift the cart from the wheels. This operation is facilitated by the provision of turned up end portions 246 at the distal ends of the runners.

With the elevator positioned as illustrated in FIG. 3, the loading operating is commenced by activating the cylinder 214 to extend the load transferring head 230 to the phantom line position in engagement with the pickup plate 24%. At or before this time, the electromagnets 232 are energized and, thus, upon engagement of the magnets with the pickup plate, a secure connection is established. Once this connection is established, the cart 234 is loaded into the car by simply energizing the cylinder 214 to retract the pickup head to the solid LEVELING MECHANISM The leveling mechanism is closely associated with the transfer mechanism and, as noted in the foregoing discussion, comprises in part the rollers 212 carried by the subcarriage 198. In addition to the rollers 212, the leveling mechanism comprises a pair of opposed channel-shaped guides 248 (see FIG. 4) fixedly mounted on the bottom member 154 by angle brackets 250. Through this mounting arrangement, the guides are fixed relative to the rotatable carriage I48 and are not free to rock with the table 170. The rollers 212, a total of four of which are provided, are received within the guides 248 when the subcarriage. 198 is nearing the retracted condition, as illustrated by the solid line representation in FIG. 3. In this condition, the interrelationship of the rollers and the guides functions to lock the table in a level condition relative to the car. The detailed construction and interrelationship of the rollers 212 and guides 248 may best be seen from FIG. 6. With reference to this figure, it is noted that the outer ends of the guides 2 .8, designated 252, are flared and resilient to facilitate entry of the rollers into the guides.

In operation, the rollers 212 and guides 248 function to maintain the load-supporting table in a level condition relative to the car so long as the transfer mechanism is retracted. Upon extension of the mechanism, however, the rollers depart from the guides and, thus, permit the table to rock. This, as will become more apparent from the subsequent discussion, facilitates the operation of the alignment mechanism. Upon retraction of the transfer mechanism, the rollers 212 reenter the guides 248 and, thus, function to automatically level the table 170.

INDEXING MECHANISM The indexing mechanism is also operationally associated with the transfer mechanism in that it functions responsive to extension and retraction of the subcarriage 198. It comprises a roller follower 254 mounted on the underside of the subcarriage and a plurality of centering spring guides 256, one of which is mounted centrally on each of the crossmembers 36, 38 and 4h, respectively. The guides are mounted on the respective crossmembers so as to be in alignment with the respective hatchways disposed around the elevator shaft. The follower 254 is so positioned relative to the guides 256 that it assumes a position to the rear of the guides (see FIG. 6 and the phantom line representation of the follower 254 at the right of FIG. 2) when the subcarriage 198 of the transfer mechanism is in the retracted condition. Thus, with the transfer mechanism retracted, the indexing mechanism does not interfere with rotation of the carriage I48. Upon extension of the subcarriage 198 during the loading or unloading operation, however, the follower 254 passes through the centering spring guide aligned therewith and, thus, functions to positively index the load supporting table 170 in alignment with the hatchway being worked. This positive alignment is momentary, in that the follower passes completely through the spring guide during extension of the subcarriage. This leaves the subcarriage free for additional alignmentwhen fully extended.

ALIGNMENT MECHANISM The alignment mechanism is designed to align the load supporting tabie 170 with the sill of a hatchway being worked. It achieves this function by rocking the table about its transverse pivot axis to achieve a smooth transition between the rollers carried by the table and the rollers 244 of the sill being worked. The structure of the alignment mechanism is made up of both sill, carried and car carried components. The sill-carried components comprise a pair of V-sbaped sockets 258 mounted in the sillof each hatchway and opening into the elevator shaft. The car carried components are mounted on the subcarriage 198 for extension therewith and comprise, in part, a pair of roliers 260 mutually engageable with the sockets 250 of a hatchway upon extension of the subcarriage.

Each of the rollers 260 is mounted on a bifurcated extension 262 slidably received in one of the box-shaped intermediate members 202 (see FIGS. 4 and 5). This arrangement and the supporting structure and mode of operation of the respective extensions correspond identically and may best be seen from FIG. 7. From this figure, it can also be seen that each exten sion is resiliently biased to a normally extended condition through means of a constant force spring-biased reel 264 having a line 266 paid out therefrom and extending around a sheave 268 to connection with an arm 270 extending laterally from the extension. The arm of each extension is pivotally secured to the extension and when in the laterally extending condition, abuts against a stop 272 mounted on the extension. The pivotal mountings of the arms are provided so that the extensions may be assembled endwise into the box-shaped intermediate members 202. The reels 264 are mounted on the rearwardly disposed crossmembers 184 and the sheaves 268 are mounted on the forwardly disposed crossmembers 184 (see FIG. 3). Brackets 274 extending upwardly from the forwardly disposed member 184 provide for the latter mounting.

In operation, whenever the subcarriage 198 is extended through means of the cylinder 214, the extensions 262 move therewith and, ultimately, engage the sockets 158 opposed thereto. Upon the latter occurrence, the elevational lateral force imparted to the extensions by the sockets functions to tilt the table 170 to a condition wherein a smooth transition is provided between the rollers 196 thereon and the rollers 244 of the opposed hatchway sill. The constant force reels are selected so that the lateral component of force will be sufficient to achieve this alignment function without unduly taxing the cylinder 214. Upon retraction of the subcarriage, the extensions 262 retract when the arm of each of the extensions is engaged by the closed end of the member 202 within which it is received. The edge of this closed end at which abutment occurs is designated in FIG. 7 by the numeral 276. It is through this abutting relationship that the extensions are moved to the fully retracted condition, as may be seen from FIG. 2 and FIG. 3.

HYDRAULIC SYSTEM The hydraulic system for the various components making up the mechanism of the present invention is carried entirely by the car 10 and is schematically illustrated in FIG. 14. With this system, the only extemai-operating connections which need be made to the car are those to supply electrical power and, possibly, electrical signals to the various electrically controlled valves.

Referring now specifically to FIG. 14, the main pump is designated therein by the numeral 278 and is shown as having an electric motor 280 in driving engagement therewith. The input of the pump and the return lines throughout the system communicate with a common reservoir, designated by the numeral 282 in all instances. The output line of the pump, designated 284, extends through a connection with a constant flow control valve 286 and a check valve 288. The check valve 288 is provided to prevent the system from bleeding back to the reservoir in the event of pump shutdown or failure. From the check valve 288, the line 284 extends to communication with a pressure relief valve 290 and all of the operating components of the system.

Connection to the hydraulic motor 168 is established through means of a line 292 and a three-position poweroperated solenoid valve 294. The vale 294 is selectively operable to provide fluid pressure to the motor to drive it in either direction or to close the supply to the motor and thus stop the motor in any desired position of rotation.

' Connection to the respective motors 84 is provided by lines 296a, 296b and 296e, respectively. Each of these lines has a check valve incorporated therein, designated by the numeral 2980, b and 0, respectively. From the point of the check valve on, only the circuit for the line 296a is shown in its entirety. It should be understood, however, that the circuits for the lines 296b and 296:: would correspond, identically, to that for the line 2960. This results because each of these lines extends to a cylinder 84 for one of the three door operating mechanisms and these mechanisms correspond identically in structure and mode of operation.

From the check valve 2980, the line 296a leads through a two-position solenoid operated valve 302 which is normally biased to a condition extending the cylinder 84 connected thereto to a condition closing the closure member therefor.

Through this arrangement, upon deactivation of the solenoid for the valve, the door normally closes. The check valve 298a prevents the cylinder from retracting in the event of circuit failure.

The hydraulic cylinder 214 for the transfer mechanism is connected to the output line 284 similarly to the connection for the cylinders 84 through means of a line 304, a check valve 306 and a two-position solenoid operated valve 308. The valve 308 is spring biased to a condition wherein the cylinder 214 is normally retracted when the solenoid is deactivated. Thus, the transfer mechanism is normally in a retracted condition. The check valve 306 is provided to prevent a cylinder from bleeding to an extended condition in the event of line failure.

It is here noted that the three-position valve 294 is of the normally closed type. Thus, upon deactivation of the solenoid operators therefor, the valve closes and the position of the hydraulic motor 168 is maintained.

CONCLUSION While the construction and mode of operation of the individual components of the present invention has been described in detail, it should be understood that the overall sequence of operation may vary considerably. Where the controls are manually operated, the sequence might vary completely for each instance of operation. Where automatic controls are provided, the sequence would in all likelihood be uniform for a particular system, but one system might vary considerably from that of another. For example, one type of system might rotate the carriage I48 to the desired position as the car is traveling between levels, while another system might not rotate the carriage until the car had reached a desired level.

We claim:

1. In combination with an elevator car movable within a shaft to and from generally oppositely disposed relationship to a hatchway, said hatchway having a door mounted thereon for slidable movement relative thereto in a predetermined path between open and closed conditions, the improvement comprising:

a. a closure member carried by the car, said member being movable between open and closed conditions in a path generally parallel to the path of the hatchway door;

b. operating means carried by the car to efi'ect the selective movement of the member between the open and closed conditions;

c. at least one pin mounted on the closure member for extension and retraction relative thereto;

d. a receptacle mounted on the hatchway door in alignment with the pin, said receptacle being mutually engageable and disengageable with said pin upon the extension and retraction thereof, respectively, said receptacle comprising an enlarged open central section adapted to receive loosely the pin upon the extension thereof and a bifurcated channel section communicating with said central section at one end thereof to resiliently grip the pin upon movement of the closure member towards the open condition, said channel section being adapted to release the pin responsive to the imparting of a predetermined excessive resistance thereto by the hatchway door; and

e. cam means disposed to automatically effect movement of said pin into and out of engagement with the receptacle responsive, respectively, to movement of the closure member out of and into closed condition.

2. In a combination according to claim 1, the improvement wherein the cam means comprises:

a. a cam follower mounted on the pin; and

b. a cam surface mounted on the car for engagement with the follower, said surface being proportioned to extend the pin upon movement of the closure member towards the open condition and to permit retraction of the pin upon movement of the closure member to the closed condition. 

1. In combination with an elevator car movable within a shaft to and from generally oppositely disposed relationship to a hatchway, said hatchway having a door mounted thereon for slidable movement relative thereto in a predetermined path between open and closed conditions, the improvement comprising: a. a closure member carried by the car, said member being movable between open and closed conditions in a path generally parallel to the path of the hatchway door; b. operating means carried by the car to effect the selective movement of the member between the open and closed conditions; c. at least one pin mounted on the closure member for extension and retraction relative thereto; d. a receptacle mounted on the hatchway door in alignment with the pin, said receptacle being mutually engageable and disengageable with said pin upon the extension and retraction thereof, respectively, said receptacle comprising an enlarged open central section adapted to receive loosely the pin upon the extension thereof and a bifurcated channel section communicating with said central section at one end thereof to resiliently grip the pin upon movement of the closure member towards the open condition, said channel section being adapted to release the pin responsive to the imparting of a predetermined excessive resistance thereto by the hatchway door; and e. cam means disposed to automatically effect movement of said pin into and out of engagement with the receptacle responsive, respectively, to movement of the closure member out of and into closed condition.
 2. In a combination according to claim 1, the improvement wherein the cam means comprises: a. a cam follower mounted on the pin; and b. a cam surface mounted on the car for engagement with the follower, said surface being proportioned to extend the pin upon movement of the closure member towards the open condition and to permit retraction of the pin upon movement of the closure member to the closed condition.
 3. In a combination according to claim 1, the improvement wherein the receptacle further comprises a bifurcated end section communicating with the central section at an end thereof opposite the bifurcated channel section, said end section being adapted to offer resistance to the passage of the extended pin therethrough and to release the pin upon the occurrence of a predetermined resistance. 